Helpful hints:
There is no need to add salt because the savoury yeast flakes have quite a salty flavour already
I also found I needed to use salt-reduced soy sauce because of this
If you can’t find arrowroot you could use corn flour. Arrowroot is preferable because it has no residual flavour and is a better thickener
If you’d like to make a mushroom gravy, simply take 150grams of button. Wash, slice and sauté them. Then add to the gravy before bringing to the boil
Taste, taste and taste to adjust seasoning

How to prepare:
Heat oil in medium saucepan over medium heat
Add onion and garlic
Cook, stirring frequently for 3 to 5 minutes
Add arrowroot, yeast flakes and soy sauce; mix well to form a smooth paste
Slowly add broth, whisking constantly to blend. Season with pepper
Add sautéed mushrooms now, if making a mushroom gravy
Bring to a boil, then reduce heat to low, gently simmer, stirring frequently for 8 to 10 minutes or until thickened